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Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

Moghimi S, Schudlo L, Chau T, Guerguerian AM - PLoS ONE (2015)

Bottom Line: Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes.Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains.Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Toronto, Ontario, Canada; Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.

ABSTRACT
Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

No MeSH data available.


Related in: MedlinePlus

The procedures involved in determining pair-wise consistency indexes.The three dimensional representation of similarity topographies was used to determine distances between points. The histogram and cumulative sum of these distances was used to determine the pair-wise consistency index (i.e. P).
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pone.0122148.g005: The procedures involved in determining pair-wise consistency indexes.The three dimensional representation of similarity topographies was used to determine distances between points. The histogram and cumulative sum of these distances was used to determine the pair-wise consistency index (i.e. P).

Mentions: In the previous phase, the consistency index assessed the consistency between all four repetitions of each musical excerpt, but partial consistency i.e., consistency among a smaller subset of the repetitions of the same musical excerpt, was not investigated by this index. To investigate partial consistency, a pair-wise consistency index was defined based on the three dimensional point representations of similarity topographies, shown in Fig. 5. A total of 360 points were available across all participants (six songs, six possible comparisons across ten participants). The pair-wise index of consistency was defined based on the distance between each pair of points across 64620 possible distances i.e.,. As shown in Fig. 5b the percent histogram of these distances illustrated the ratio of points falling at each distance from each other, and the cumulative sum of this histogram (Fig. 5c) was used to determine the threshold value. The threshold values were selected so that no more than 10% of the point pairs were within the threshold distance from each other. Ultimately, the probability of the pairs corresponding to the same musical excerpt was estimated given that these points were at a distance less than each threshold value. For example, at a threshold of 3.7 (i.e., 10% cut off shown in Fig. 5c), the ratio of the points belonging to the same musical excerpt at a distance less than 3.7 was determined to all points which were at less than 3.7 distance. The probability estimations were made for a ratio of 1% to 10%, and a step size of 0.5%. For each threshold value, the estimated probabilities () were stored in a vector which was referred to as P. The P vector represented the ratio of the pair-wise consistency indexes for the same musical excerpt, those distances were at lower than x% (x = 1, 1.5, 2,…, 10) from each other.


Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

Moghimi S, Schudlo L, Chau T, Guerguerian AM - PLoS ONE (2015)

The procedures involved in determining pair-wise consistency indexes.The three dimensional representation of similarity topographies was used to determine distances between points. The histogram and cumulative sum of these distances was used to determine the pair-wise consistency index (i.e. P).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383450&req=5

pone.0122148.g005: The procedures involved in determining pair-wise consistency indexes.The three dimensional representation of similarity topographies was used to determine distances between points. The histogram and cumulative sum of these distances was used to determine the pair-wise consistency index (i.e. P).
Mentions: In the previous phase, the consistency index assessed the consistency between all four repetitions of each musical excerpt, but partial consistency i.e., consistency among a smaller subset of the repetitions of the same musical excerpt, was not investigated by this index. To investigate partial consistency, a pair-wise consistency index was defined based on the three dimensional point representations of similarity topographies, shown in Fig. 5. A total of 360 points were available across all participants (six songs, six possible comparisons across ten participants). The pair-wise index of consistency was defined based on the distance between each pair of points across 64620 possible distances i.e.,. As shown in Fig. 5b the percent histogram of these distances illustrated the ratio of points falling at each distance from each other, and the cumulative sum of this histogram (Fig. 5c) was used to determine the threshold value. The threshold values were selected so that no more than 10% of the point pairs were within the threshold distance from each other. Ultimately, the probability of the pairs corresponding to the same musical excerpt was estimated given that these points were at a distance less than each threshold value. For example, at a threshold of 3.7 (i.e., 10% cut off shown in Fig. 5c), the ratio of the points belonging to the same musical excerpt at a distance less than 3.7 was determined to all points which were at less than 3.7 distance. The probability estimations were made for a ratio of 1% to 10%, and a step size of 0.5%. For each threshold value, the estimated probabilities () were stored in a vector which was referred to as P. The P vector represented the ratio of the pair-wise consistency indexes for the same musical excerpt, those distances were at lower than x% (x = 1, 1.5, 2,…, 10) from each other.

Bottom Line: Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes.Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains.Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions.

View Article: PubMed Central - PubMed

Affiliation: University of Toronto, Toronto, Ontario, Canada; Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.

ABSTRACT
Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

No MeSH data available.


Related in: MedlinePlus